Require python-daemon version at least 2.0.4

Change-Id: I69f8bbd9d78abdebd212f2e74d46178f592fc916
diff --git a/requirements.txt b/requirements.txt
index 81257ab..b24d171 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@
 GitPython>=0.3.2.1
 lockfile>=0.8
 ordereddict
-python-daemon<2.0
+python-daemon>=2.0.4
 extras
 statsd>=1.0.0,<3.0
 voluptuous>=0.7